1. Field of the Invention
The present invention relates to a method of making an electromagnetic assembly comprising at least one sheet stack made of ferromagnetic material and at least one additional component in the form of a magnet pole or stator packet of a stator linear motor for a magnetic levitation train and to the electromagnetic assembly produced by that method.
2. Prior Art
In a known method of this type (DE 31 10 339 C2) for manufacturing stator packets, firstly strips made from silicated magnetic steel sheets are provided preferably on both sides with additional adhesive layers, which consist for example of a pre-hardened duroplastic adhesive and if necessary are already applied in the rolling mill in a complex, expensive working step. The manufacture of sheet stacks is then carried out in that sheet blanks or lamellae are stamped out from such sheet strips drawn off from coils (drums), and these are then combined into stacks and thereafter, by heating and simultaneous pressure, are mechanically securely connected together to form a sheet stack. Then the finished sheet stacks are additionally provided with a coating of an epoxy resin or the like, in order to provide the cut edges of the plates revealed during stamping with an additional anti-corrosion layer. Finally the individual sheet stacks are connected by gluing, screwing, clamping or the like to other components, in particular to crosspieces intended for their attachment on a travel path, forming the finished stator packet. In order to obtain sufficient mechanical stability as a rule disadvantages from the electromagnetic stand point must be accepted, e.g. with respect to the electromagnetically unfavorable cross-sectional shapes of the groove which are however desirable for attachment of the electrical conductors.
Magnet poles for long stator linear motors are produced in a similar way, finished sheet stacks then being provided with windings and pole jaws or the like, and connected. In this case also compromises must be accepted between mechanical stability and electromagnetic properties, e.g. with respect to the geometry of the iron core made out of the sheet stack, which is necessary for reliable assembly of the windings, and yet entails undesirable magnetic dispersion effects.
Due to the installations required for coating the strips of magnetic steel sheet, methods of this type involve high investment costs. A further disadvantage is that the waste occurring during stamping is provided with an adhesive layer, which ought to be avoided for reasons of environmental protection, and which prevents properly-classified recycling of the sheet steel waste. Finally, the known method requires numerous successive partial steps, which respectively serve a pre-selected partial purpose.
The object underlying the invention is therefore to alter the above described method for manufacturing magnet poles and stator packets in such a way that lower investment costs and fewer individual steps are required and better adaptation is possible to the functions of the various components involved. Moreover, high mechanical strength and high resistance to external weathering influences are to be achieved.
The method according to the invention provides an electromagnetic assembly in the form of a magnet pole or stator packet of an extended stator linear motor for a magnetic levitation train, which includes at least one sheet stack made of ferromagnetic material and at least one additional component. This method comprises the steps of:
a) assembling the at least one sheet stack from a plurality of raw magnetic steel sheets;
b) positioning the at least one sheet stack together with the at least one additional component, if necessary using auxiliary positioning means, in a tool; and then
c) feeding a hardenable mixture into the tool and hardening or hardening out of the hardenable mixture according to a pressure-gelling method in one single working step so that the steel sheets are connected together to form a finished sheet stack surrounded by the hardenable mixture and the finished sheet stack is connected to the at least one additional component to form the electromagnetic assembly with final electrical, magnetic, mechanical and/or geometric properties.
Further advantageous features of the invention will become apparent from the dependent claims.